Farm history and breeding management influences on the intensity and specific diversity of nematode infection of dairy goats.

Sixteen dairy-goat farms were investigated in the centre-west of France for nematode infection. The intensity of infection was assessed by means of faecal egg counts and nematode counts at necropsy for digestive-tract nematodes and faecal larval counts for Muellerius capillaris. The specific diversity and prevalence were estimated by worm counts of 28 necropsied culled goats. The history and breeding management were recorded by means of a questionnaire. Specific diversity was estimated on two culled goats. Specific diversity and prevalence were related to the area of permanent pasture, age of farm, and to the number of goats introduced at the establishment of the farm. The most common species were Teladorsagia circumcincta and Trichostrongylus colubriformis. Teladorsagia trifurcata was absent from zero-grazing farms. Trichostrongylus vitrinus and Oesophagostomum venulosum were present in significant numbers on only one farm out of 16. The importance of Haemonchus contortus varied from farm to farm. The historical and breeding management factors that influenced the proportions of the most common species were the age of farm, size of flock, percentage of Alpine breed, duration of kidding period, age of goats and number of farms of origin. Age of farm and size of flock exerted opposing effects on the proportions of Teladorsagia circumcincta and Trichostrongylus colubriformis, respectively. The historical and breeding management factors were confounded and their respective effects on infection and the proportions of species was difficult to assess.